Honda’s Variable Cylinder Management i-VTEC

Honda is famous for their 4-cylinder VTEC and i-VTEC engines, but they also have V6 engines in their stables. The Acura NSX had a 3.2 litre V6 and the current shark-faced top of the range CBU Honda Accord on our markets has a 3.0 litre SOHC VTEC V6 engine with the code J30A under the hood. However, USDM and Japanese versions of our Accord (actually called the Honda Inspire in Japan) has a new i-VTEC version of the J30A.
What’s special about this new J30A with i-VTEC is it comes with Honda’s Variable Cylinder Management technology. What happens is under low engine load the i-VTEC system disables 1 of the two cylinder banks, effectively turning the engine into a 1.5 litre inline-3 instead of a 3.0 litre v6. What Honda defines as low engine load is actually a mixture of vehicle speed, engine speed and throttle position patterns. The disabled rear cylinder bank is sealed by idling the intake and exhaust valves and no fuel is injected.

Now everyone knows 3-cylinder straight engines have alot of vibrations due to the cylinder count being unbalanced. What happens is vibration is cancelled out by the active engine mounting. This engine mounting rocks in a similiar motion to dampen the vibrations. Noise is also cancelled out with a special speaker which emits the exact opposite phase of the engine noise read from a microphone. Pretty funky stuff.

What you get is a 3.0 V6 with the fuel economy of a 2.4 litre inline 4 cylinder under normal mixed city and highway driving situations. This is approximately 11.6km per litre, compared to the Accord 2.4 running the K24A which manages 12km per litre.

Getting down to the basic performance stats, the J30A makes 250 horsepower and 296Nm of torque.

After dabbling for years in the IT industry, Paul Tan initially began this site as a general blog covering various topics of personal interest. With an increasing number of readers paying rapt attention to the motoring stories, one thing led to another and the rest, as they say, is history. An avid electronic gadget aficionado as well as big-time coffee lover, he's also the executive producer of the Driven motoring TV programme.

Wonder how much price difference this new technology will cost? And also wonder if the local Honda mechanics and also the non-Honda-authorised-but-experienced-enough-to-maintain-Honda-cars mechanics would be able to handle such a radical change in technology.

But definitely sounds very cool, especially when telling people about how it works.

Wow, using only 3 cylinders instead of all 6, and noise cancellation. All so cool, wonder how will the engine sound should the noise cancellation gadget go out of order? I like the 3 cylinder idea though, it's really practical and saves a lot on fuel.

Actually this noise cancellation system is simple. It is actually a MIC, recorder and Speakers. At first Records the engine sound using a MIC and then send back the same Signal or Waves to the engine. To repeat this proceed frequently.

But it is not easy to apply it on vehicle, due to space, environment and durability issues.

Honestly Syamen, you can't compare a Savvy engine against a Honda 3.0. That would not be a fair comparison =)

I believe Mercedes has something similar in the S-Class engines. But if you guys think that the 3.0 veriable cylinder engine is spectacular, wait till you read about it's hybrid cousin (the 3.0 V6 hybrid available on the US Accord). The engine will completely switch off during idling and then run on electric motors at low loads. Its not just fuel efficient, but is also very environmental friendly, especially during idling as there are no emissions. Cool, huh??

Hey, if they can have noise cancellation in cars & highway, perhaps you can find similar application against your noisy neighbour or nagging "significant other", hehe….. Just imagine, your bf/gf start nagging, just shut them up by pointing the noise cancellation device against them.

A question please? The noise cancellation works only in 3 cylinder mode right? Meaning that there is less noise or no noise at all from the engine combustion during idling (except for exhaust & intake note)? Must be weird to hear only exhaust note, but not accompanied by the engine combustion sound.

Actually, I read about this noise cancellation device a few years ago. I think it was Nissan who was researching this technology. The device was fitted under the front seats (mic and speaker) and it picked up the sound emanating from the engine compartment and sends back the same frequency in real time.

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